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Traction control allowed loss of contact on wet roard

Traction control allowed loss of contact on wet roard

Submitted by pencil2man on Sun, 2013-07-14 06:43

I was surprised the other night while showing off the acceleration of my 85 after a rainstorm that there were several times the wheel broke loose from the pavement. Slight fishtailing was felt. i would have thought that the traction control would be able to prevent this unsafe condition...... understanding that i was showboating... safely.

emd1234 |
14 July 2013

The computer probably doesn't know that you were "showboating" and that the road was wet at the time, and to my knowledge is a reactive system. By that, I mean, that it doesn't know that it needs to engage until after it senses wheel slip. Your fishtailing would have probably been much worse had the traction control been turned off.

lolachampcar |
14 July 2013

try it and see :)

cfOH |
14 July 2013

There are limits to which technology can save us from ourselves.

phat78boy |
14 July 2013

Lol. I don't think there is a system developed, that can fit nicely in a car, which will keep you completely safe while showboating on a wet road.

carlk |
14 July 2013

Showboating? Didn't you want it to float a bit? I told you this car is smart.

July10Models |
14 July 2013

My S85 did this on uneven pavement as I dusted a panamara S turbo on a two lane to a single lane bridge. It was the first time the S fish tailed on me and the wheels growled like a beast. A few miles down the road the panamara driver was all thumbs up as he passed me north of triple digits. This car was made to showboat.

david.cheney |
14 July 2013

heh.. during my test drive I got the usual P85. About 50 yards up the highway on-ramp - which was damp - I stepped on it. The back end broke look just that quick and started to drift left hard.. a real surprise as I am not aware of any left force. I have experience driving on ice so I got it back into control in a hurry. Not my heart though. I had been doing maybe 20 when I stepped, and I wasn't trying to hit the floorboards. Never tried it again, and bought a 40 lol. Nah, I'm not a wimp, just 'poor' ;p

david.cheney |
14 July 2013

oh, yeah.. dunno if traction control was on..

npham1212 |
14 July 2013

@pencil2man .

On my test drive back in June, after getting the Ok from the Tesla manager, I floored the pedal to quickly merge into the highway (which has 65MPH limit and everyone was doing around 80+MPH).

My objectives were a) to experience that feeling of jetting from 0 to 60MPH in a few seconds that I have read about so many times, and b) obviously to "quickly merge into the highway".

In a little more than a blink, little did I know, I passed 100MPH (an unintended objective), I did notice that same "Slight fishtailing was felt" near the end approaching the top speed. All of this took place in just a few exhilarating seconds.

What seems interesting to me is in my case the weather was great, sunny and dry.

cfOH |
14 July 2013

You all might be discussing two different sensations. "Fishtailing" is when the rear tires break traction and the rear end moves out of the line of travel.

The feeling that @npham1212 experienced may instead be what a lot of people here call "floatiness" of the rear end at high speeds, especially when making lateral corrections on the steering wheel. A general sense of the back end of the car being slightly disconnected from the chassis. That lack of connectedness was partly what the Plus handling package was supposed to damp down.

J.T. |
14 July 2013

@cfOH

I believe that inaccurate tire inflation was determined to be one possible cause of the "floatiness." Some cars were delivered with tires inflated to 54 psi instead of 42. I don't own a P but my tires wre all at 49 instead of 42. Once I made the adjustment my ride was markedly improved. This is a little off the topic of traction control but I thought many might benefit from the info.

stsanford |
14 July 2013

Thanks jtodman, I have been having what I would call "twitchiness" from the car on grooved pavement and sometimes on non-grooved and it feels the same. Like the car is darting around (subtly) looking for traction. Will check my pressures, might be that simple a fix. It's minor (I have been driving 911s for years so I have a natural reflex developed)

TeslaTap.com |
14 July 2013

Another thought - the P85 has "sport traction control". It's not quite clear what the difference is from the 40/60/85, but it may be a bit less aggressive? I've only had it activate on dirt roads (that all the cars seem to on this road), and that was at 15 MPH (with a 60).

As a 'green' driver, sudden and drastic change (accelerating or decelerating) in speed is one thing I rarely do, thus that this one occasion of "flooring from 15MPH to 100MPH in few seconds with an MS" was my first ever. Prior to that, I have had absolutely no personal exposure to either "floatiness" or "fishtailing" or "twitchiness"

Can you, or anyone, please shed some more details on these sensations?
How common are these symptoms on existing high performance ICE's?
In your opinions, is the MS any more sensitive / inclining to these symptoms?

Jewsh |
15 July 2013

I'm actually surprised that you didn't end up in a ditch. This car has a huge amount of power and for Tesla to keep the horsies under control under almost every circumstance is a feat. I actually think the TC is pretty well perfect. It's already saved me from myself twice.

cfOH |
15 July 2013

@npham1212 Well, short of a primer on performance driving, I'm not sure what to tell you except that cars with lots of torque being applied to not-very-wide rear tires going around a turn on slick pavement will nearly always* exhibit some "stepping out" of the rear end.

*Traction control and stability control can help mitigate these, and they likely kept you from wrecking in this case, but they can only react to what they experience has happened, not what you're anticipating doing. In other words, they can help keep bad situations from getting worse, but they can't keep you from overextending the car's traction and suspension in the first place. I would suggest taking your car to a "performance driver's ed" place and learn the dynamics of your vehicle. It'll help you understand what your car can and, more importantly, cannot do. You'll also likely think it's a total hoot.

npham1212 |
15 July 2013

@Jewsh, despite of my 'green' driving practice which could be equated to 'boring' driving by many, I'm an excellent and considerate driver. For 30 +years driving and traveled extensively domestic and international, I have never caused any accident.
The MS test drive fast acceleration wasn't what it may sound like: "100MPH? you must be crazy!"
It was a reflection of what the Tesla MS can do, not at all of what I can do ;-)

@cfOH, thank you for the insights. I'm looking for a general knowledge on this subject matter, not for the intention of doing sudden accelerating. Knowing what it can do, will enable one to decide when to properly use it in justified conditions, i.e. getting out of the danger zone.
"Know your bike's limits and your own limits." was the most important thing that I've previously learned during my motorcycle training days ;-)

LionPowered |
15 July 2013

The test drive cars in Denver are limited to 80 MPH. It's way too easy to go way too fast until you get used to the car. Then I guess it goes from being accidental to on purpose for some :-)

The ability to set the limit will show up in the touch screen user interface in a future release. I wouldn't mind being able to use it to govern myself as well as a valet.

npham1212 |
15 July 2013

@Lion... "govern a valet..." @ 35MPH ;-)

Roamer@AZ USA |
15 July 2013

The first time I accelerated the car I thought ....going to be many people used to gutless 4 bangers that will get in trouble with all this torque.

Lots of torque and wet tires can be dangerous if you don't manage your use of the available power. Computers are nice but they cant save you from every issue.